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Deep Brain Stimulation for Movement Disorders

Deep Brain Stimulation for Movement Disorders

Deep Stimulation for Movement Disorders

Overview Deep brain stimulation (DBS) is a surgical procedure to implant a pacemaker-like device that sends electrical signals to brain areas responsible for body movement. Electrodes are placed deep in the brain and are connected to a stimulator/battery device. Similar to a heart pacemaker, a neurostimulator uses electric pulses to help regulate brain activity. DBS can help reduce the symptoms of , slowness of movement, stiffness, and walking problems caused by movement disorders. It may be a treatment option for people who have Parkinson’s disease, , or and whose symptoms are not well controlled with medication. Successful DBS allows people to better manage their symptoms, reduce their medications, and improve their quality of life.

What is deep brain stimulation? In deep brain stimulation, electrodes are placed in a specific area of the brain (usually the ) depending on the symptoms being treated. The electrodes are placed on both the left and right sides of the brain through small holes made at the top of the skull. The electrodes are connected by long extension wires that are passed Figure 1. Overview of a deep brain stimulator (DBS). under the skin and down the neck to a battery- Electrodes are placed deep within the brain through small holes in the skull. The electrodes are connected by an powered stimulator under the skin of the chest (Fig. extension wire to a battery-powered stimulator placed 1). When turned on, the stimulator sends electrical under the skin of the chest. Because the left side of the pulses to block the faulty nerve signals causing brain controls the right side of the body and vice versa, , rigidity, and other symptoms. DBS is commonly performed on both sides of the brain.

A deep brain stimulator system has three parts that are implanted inside the body: The patient uses a handheld controller to turn the DBS system on and off. The doctor programs the • Neurostimulator – a programmable battery- stimulator settings with a wireless device. The powered pacemaker device that creates electric stimulation settings can be adjusted as a patient’s pulses. It is placed under the skin of the chest condition changes over time. Unlike other surgeries, below the collarbone or in the abdomen. such as or , DBS does not • Lead – a coated wire with a number of damage the brain tissue. Thus, if better treatments electrodes at the tip that deliver electric pulses develop in the future, the DBS procedure can be to the brain tissue. It is placed inside the brain reversed. and connects to an extension wire through a small hole in the skull. DBS is very effective at reducing , the • Extension – an insulated wire that connects uncontrolled wiggling movements caused by high the lead to the neurostimulator. It is placed doses of levadopa medication. Typically, DBS will under the skin and runs from scalp, behind the help make your symptoms less severe so that lower ear, down the neck, and to the chest. medication doses may be used.

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Electro des can be placed in the following brain areas (Fig 2):

• Subthalamic nucleus (STN) – effective for tremor, slowness, rigidity, dystonia and . Most commonly used to treat Parkinson’s disease. • (VIM) – effective for tremor. It is often used to treat essential tremor. • (GPi) – effective for tremor, slowness, rigidity, dystonia and dyskinesia. It is used to treat dystonia and Parkinson’s disease.

Who is a candidate? You may be a candidate for DBS if you have:

• a movement disorder with debilitating symptoms (tremor, stiffness) and your medications have begun to lose effectiveness. • troubling “off” periods when your medication

wears off before the next dose can be taken. • troubling “on” periods when you develop Figure 2. A cross section of the brain. Normal muscle medication-induced dyskinesias (excessive tone, movement, timing, and coordination depend on wiggling of the torso, head, and/or limbs). complex electrical circuits or feedback loops in the brain. The basal ganglia are responsible for activating and DBS may not be an option if you have severe inhibiting these feedback loops. untreated depression, advanced dementia, or if you In Parkinson’s disease, parts of the basal ganglia are have symptoms that are not typical for Parkinson’s either under- or over-stimulated. Normal movement is disease. replaced by tremor, rigidity and stiffness. DBS of specific ganglia alters the abnormal electrical circuits and helps DBS can help treat many of the symptoms caused stabilize the feedback loops, thus reducing symptoms. by the following movement disorders:

with multiple physicians, nurses, and surgeons. The • Parkinson’s disease: tremor, rigidity, and team discusses the best treatment plan for each slowness of movement caused by the death of patient. If the team agrees that you are a good dopamine-producing nerve cells responsible for candidate for DBS, you will be contacted to relaying messages that control body movement. schedule an appointment with a neurosurgeon. • Essential tremor: involuntary rhythmic

tremors of the hands and arms, occurring both at rest and during purposeful movement. Also Who performs the procedure? may affect the head in a “no-no” motion. Deep brain stimulation surgery is performed by a • Dystonia: involuntary movements and neurosurgeon who has specialized training in prolonged muscle contraction, resulting in functional . The surgical team also twisting or writhing body motions, tremor, and includes a neurologist. abnormal posture. May involve the entire body, or only an isolated area. Spasms can often be The surgical decision suppressed by “sensory tricks,” such as Seek treatment at a medical center that offers a touching the face, eyebrows, or hands. team approach and the full range of treatment options including medication, surgery, and A team of specialists including a neurologist, rehabilitation (physical, exercise, voice, balance). neuropsychologist, and neurosurgeon will evaluate your condition to determine if surgery is an option. The timing of when to consider DBS surgery is Your thinking and memory, current medications, different for each patient. If you have severe motor and general health will be evaluated. You will be disability despite optimal medications, then surgery videotaped performing a variety of movements should be considered. DBS should not be thought of (walking, finger tap, rising from a chair) while on as a last resort. As Parkinson’s disease progresses, and off medication. Your symptoms and abilities are DBS is no longer an option if your symptoms don’t measured using the Unified Parkinson Disease respond to medication, or if you are severely Rating Scale (UPDRS). disabled even in the best “on” state. And unlike other surgeries (pallidotomy, thalamotomy) that After your evaluation and videotaping is complete, damage brain tissue, DBS is reversible and can be your case will be discussed at a monthly conference turned off or removed if necessary.

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The surgery is performed in two stages. Stage 1 is implantation of the electrodes in the brain. About one week later, Stage 2 is performed. This includes implantation of the stimulator device in the chest and tunneling of the wires to the neck.

What happens before surgery? You will typically undergo tests (e.g., blood test, electrocardiogram, chest X-ray) several days before surgery. An MRI scan of your brain will be performed. In the doctors office you will sign consent forms and complete paperwork to inform the surgeon about your medical history, including allergies, medicines, anesthesia reactions, and previous surgeries.

Stop taking all non-steroidal anti-inflammatory medicines (Naprosyn, Advil, Motrin, Nuprin, Aleve, etc.) 1 week before surgery. Stop smoking, chewing tobacco, and drinking alcohol 1 week before and 2 weeks after surgery because these Figure 3. A stereotactic frame is attached to the activities can cause bleeding problems. You may patient’s head with four pins. also need to have clearance from your primary care physician or cardiologist if you have a history of other medical or heart conditions. No food or drink, including your Parkinson’s medication, is permitted a fter midnight the night before surgery.

Try to get a good night’s sleep. The DBS surgery involves multiple steps and lasts most of the day, during which you will be awake and off medication.

Morning of surgery • Shower using antibacterial soap. Dress in freshly washed, loose-fitting clothing. • Wear flat-heeled shoes with closed backs. • If you have instructions to take regular medication the morning of surgery, do so with small sips of water. • Remove make-up, hairpins, contacts, body piercings, nail polish, etc. • Leave all valuables and jewelry at home (including wedding bands). • Bring a list of medications (prescriptions, over- the-counter, and herbal supplements) with dosages and the times of day usually taken. • Bring a list of allergies to medication or foods.

Arrive at the hospital 2 hours before your scheduled Figure 4. A skin incision (dashed line) is made across the surgery time to complete the necessary paperwork top of the patient’s head. Two small burr holes (circles) and pre-procedure work-ups. An anesthesiologist are drilled in the skull to pass the electrode into the brain. will talk with you and explain the effects of anesthesia and its risks. An intravenous (IV) line will be placed in your arm. Step 1: attach stereotactic frame The procedure is performed stereotactically, which What happens during surgery? requires attaching a frame to your head. While you For stage 1, implanting the electrodes in the brain, are seated, the frame is temporarily positioned on the entire process lasts 5 to 7 hours. The surgery your head with Velcro straps. The four pin sites are generally lasts 3 to 4 hours. injected with local anesthesia to minimize

discomfort. You will feel some pressure as the pins are tightened (Fig. 3).

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Step 2: MRI or CT scan You will then have an imaging scan, using either computerized tomography (CT) or magnetic resonance imaging (MRI). A box-shaped localizing device is placed over the top of the frame. Markers in the box show up on the scan and help pinpoint the exact three-dimensional coordinates of the target area within the brain. The surgeon uses the MRI / CT images and special computer software to plan the trajectory of the electrode.

Step 3: skin and skull incision You will be taken to the operating room. You will lie on the table and the stereotactic head frame will be secured. This prevents any small movements of your head while inserting the electrodes. You will remain awake during surgery. Light sedation is given to make you more comfortable during the initial skin incision, but then stopped so that you can talk to the doctors and perform tasks.

The hair is shaved about an inch wide along the incision line. A skin incision is made across the top of your head to expose the skull. Using a drill, two quarter-sized burr holes are made on the left and right sides of the skull (Fig 4). These holes allow the electrodes to be passed through the brain.

Step 4: insert electrode in the brain Through the small hole, a recording electrode is Figure 5. An arc-shaped device is attached to the frame to inserted into the brain. Based on calculations from plot the coordinates and drive the electrode to the exact the MRI / CT scans and the planning computer, the location and depth in the brain. The recording electrode electrode is inserted to a precise depth and angle detects the electrical waveforms of nerve cells. inside the brain (Fig 5). The brain itself does not feel , so you should not feel any discomfort.

Accuracy of the electrode placement is confirmed by a number of tests. You may be asked to lift your arms or legs, or count numbers. The surgical team will also listen for the correct nerve cells. The recording electrode can hear the brain cells firing and display the waveforms on a computer. This is the most time-consuming part of the procedure. It must be repeated for both the left and right sides of the brain. Your patience and cooperation will help the surgical team do their job.

St ep 5: stimulate the brain cells Once the exact nerve cells are located, the surgeon replaces the recording electrode with a permanent DBS electrode/lead (Fig. 6). Test stimulation is performed. You will be asked if you feel any of your symptoms lessen or completely go away.

Step 6: closure When the team is satisfied with electrode placement, a plastic cap is placed over the burr hole to hold the lead in place. A coil of wire is left under the scalp for later attachment to the extension wire Figure 6. The electrode tip is placed precisely in the and the stimulator. The scalp incision is closed with subthalamic nucleus (STN). A coil of lead wire is left under sutures or staples and a bandage is applied. the skin for later attachment to the stimulator.

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What happens after surgery? What are the risks? After surgery, you may take your regular dose of No surgery is without risks. General complications Parkinson’s medication immediately. You are kept of any surgery include bleeding, infection, blood overnight for monitoring and observation. Most clots, and reactions to anesthesia. Complications patients are discharged home the next day. related to placement of the DBS lead include seizures, infection, and a 1% chance of bleeding in During the recovery time after implanting the the brain. electrodes, you may feel better than normal. Brain swelling around the electrode tip causes a lesion Reasons for which you might need additional effect that lasts a couple days to weeks. This surgery include breakage of the extension wire in temporary effect is a good predictor of your the neck; parts may wear through the skin; and outcome once the stimulator is implanted and removal of the device due to infection or programmed. mechanical failure. Additionally, the battery will need to be replaced every 2 to 5 years. Some DBS About a week later, you will return to the hospital systems have a rechargeable battery that may last for outpatient surgery to implant the stimulator in up to 9 years. the chest/abdomen. This surgery is performed under general anesthesia and takes about an hour. DBS may also cause worsening of some symptoms Patients go home the same day. such as speech and balance impairments. In some patients with Parkinson’s, DBS may cause or Step 7: implant the stimulator worsen depression. If you develop any side effects You will be taken to the OR and put to sleep with from a stimulation adjustment, you need to return general anesthesia. A portion of the scalp incision is to the office for further programming. reopened to access the leads. A small incision is made near the collarbone and the neurostimulator What are the results? is implanted under the skin. The lead is attached to Successful DBS is related to 1) appropriate patient an extension wire that is passed under the skin of selection, 2) appropriate selection of the brain area the scalp, down the neck, to the stimulator/battery for stimulation, 3) precise positioning of the in the chest or abdomen. The device will be visible electrode during surgery, and 4) experienced as a small bulge under the skin, but it is usually not programming and medication management. seen under clothes.

For Parkinson’s disease, DBS of the subthalamic

You should avoid arm movements over your nucleus improves the symptoms of slowness, shoulder and excessive stretching of your neck tremor, and rigidity in about 70% of patients [1]. while the incisions heal. Pain at the incision sites Most people are able to reduce their medications can be managed with medication. and lessen their side effects, including dyskinesias.

It has also been shown to be superior in long term

Step 8: program the stimulator management of symptoms than medications [2].

About 10 days after surgery, you will be scheduled for an office visit. The stimulator will be For essential tremor, DBS of the thalamus may programmed and your medication dosage will be significantly reduce hand tremor in 60 to 90% of adjusted. You may be asked to stop taking your patients and may improve head and voice tremor. medications for up to 12 hours before the programming session. This is done to increase the DBS of the globus pallidus (GPi) is most useful in effectiveness of the programming in reducing your treatment of dyskinesias (involuntary wiggly usual symptoms. It is important that you work with movements), , as well as other tremors. the neurologist and nurse to adjust your For dystonia, DBS of the GPi may be the only medications and refine the programming. You will effective treatment for debilitating symptoms. return to the office every 3 weeks for programming. Though recent studies show little difference

It typically takes 3 to 4 programming sessions to between GPi-DBS and STN-DBS. attain maximum symptom control while minimizing side effects. Patients report other benefits of DBS. For example,

better sleep, more involvement in physical activity,

Most people don't feel the stimulation as it reduces and improved quality of life. their symptoms. However, some people may feel a brief tingling sensation when the stimulator is first Recent research in animals suggest that DBS may turned on. “protect” or slow the death of dopamine nerve cells

[4]. While the scientific data is inconclusive,

It’s important to remember that Parkinson’s disease observation of DBS patients show potential slowing is progressive and symptoms get worse over time. of the disease relative to their pre-DBS condition.

You will return to the neurologist’s office periodically to adjust the stimulation settings.

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Living with a stimulator Links Once the DBS has been programmed, you are sent www.parkinson.org home with instructions for adjusting your own stimulation. The handheld controller allows you turn www.wemove.org the stimulator on and off, select programs, and adjust the strength of the stimulation. Most patients www.youngparkinsons.org keep their DBS system turned on 24 hours day and night. Some patients with essential tremor can use www.essentialtremor.org it during the day and turn off the system before bedtime. Your doctor may alter the settings on Glossary follow-up visits if necessary. basal ganglia: a mass of nerve cell bodies (gray matter) located deep within the white matter of If your DBS has a rechargeable battery, you will the cerebrum. Has connections with areas that need to use a charging unit. On average charging subconsciously control movement. time is 1 to 2 hours per week. You will have a bradykinesia: slowness of movement, impaired choice of either a primary cell battery or a dexterity, decreased blinking, drooling, rechargeable unit and you should discuss this with expressionless face. you surgeon prior to surgery. dopamine: a that passes messages from neuron to neuron across Just like a cardiac pacemaker, other devices such synapses. as cellular phones, pagers, microwaves, security dyskinesia: abnormal involuntary movements that doors, and anti theft sensors will not affect your may be caused by either high or low levels of stimulator. Be sure to carry your Implanted Device anti-parkinson medication in patients with PD. Identification card when flying, since the device is electrode: a conductor that carries electrical detected at airport security gates. current. globus pallidus interna (GPi): nuclei in the brain Sources & links that regulate muscle tone; part of the basal If you have more questions or would like to ganglia. schedule an appointment with one of our neuron: basic unit of the , neurosurgeons, please call (515) 241-5760. Our composed of a cell body, dendrites, and axon; offices are located on the Iowa Methodist Campus. also called a nerve cell. pallidotomy: a surgical procedure that destroys Sources the nerve cells in the globus pallidus of the brain. 1. Deep-Brain Stimulation for Parkinson's Disease Used to treat the symptoms of Parkinson’s Study Group: Deep-brain stimulation of the disease. subthalamic nucleus or the pars interna of the stereotactic: use of three-dimensional coordinates globus pallidus in Parkinson's disease. N Engl J to precisely locate deep brain structures. Med 345:956-63, 2001 substantia nigra: an area of the brain where 2. Weaver FM, Follett K, Stern M, et al. Bilateral dopamine is produced. Deep Brain Stimulation vs Best Medical thalamus: a relay station for all sensory messages for Patients With Advanced Parkinson Disease: that enter the brain; part of the basal ganglia. A Randomized Controlled Trial. JAMA 301:63- thalamotomy: a surgical procedure that destroys 73, 2009 the nerve cells in the thalamus of the brain. Used 3. Deuschl G, Schade-Brittinger C, Krack P, et al. to treat the symptoms of tremor or pain. A Randomized Trial of Deep-Brain Stimulation for Parkinson’s Disease. N Engl J Med 355:896- 908, 2006 4. Spieles-Engemann AL, Behbehani MM, Collier TJ, et al. Stimulation of the rat subthalamic nucleus is neuroprotective following significant nigral dopamine neuron loss. Neurobiol Dis 39(1):105-15, 2010

updated > 2.2013 reviewed by > George Mandybur, MD, Mayfield Clinic / University of Cincinnati Department of Neurosurgery, Ohio Maureen Gartner, RN, University of Cincinnati Department of , Ohio

Mayfield Certified Health Info materials are written and developed by the Mayfield Clinic & Spine Institute. We comply with the HONcode standard for trustworthy health information. This information is not intended to replace the medical advice of your health care provider. © Mayfield Clinic 1998-2013.

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